Pushing device in double cylinder circular knitting machines

ABSTRACT

Pushing device in double-cylinder circular knitting machines, comprising a vertical cylinder, coaxially fixed above the two needle cylinders, a piston slideably mounted within said cylinder, and means for hydraulically feeding said cylinder. A pair of vertical rods, placed at a short distance from each other, are coupled to piston so as to rotate around its axis, said rods passing through respective passages perforated within a body, rigidly fastened to the needle cylinders, and supporting beneath them a member arranged to engage (by means of points) with the articles under manufacture.

9 M4 1 NW 6 Aug. 7, 1973 9/1966 6/1966 9/1940 Great Britain.............. ABSTRACT 1 Claim, 1 Drawing Figure Primary Examiner-James Kee Chi Attorney-Guido Modiano and Albert .losif Pushing device in double-cylinder circular knitting machines, comprising a vertical cylinder, coaxially fixed above the two needle cylinders, a piston slideably mounted within said cylinder, and means for hydraulically feeding said cylinder. A pair of vertical rods, placed at a short distance from each other, are coupled to piston so as to rotate around its axis, said rods passing through respective ,passages perforated within a body, rigidly fastened to the needle cylinders, and supporting beneath them a member arranged to engage (by means of points) with the articles under manufacture.

66/149 R D04b 15/88 66/149 R, 149 S,

FOREIGN PATENTS OR APPLICATIONS Francesco Lonati, Via S. Polo l1, Brescia, Italy Oct. 12, 1971 [211 App]. No.: 188,693

References Cited UNITED STATES PATENTS 11/1954 Butler...........

Rossler.................

ltaly United States Patent [191 Lonati PUSIIING DEVICE IN DOUBLE CYLINDER CIRCULAR KNITTING MACHINES Foreign Application Priority Data Oct. 21, 1970 5/1966 Dodds et al...

[76] inventor:

[22] Filed:

[51] Int. [58] Field of Search.......................

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INVENTOR F RANCESCO LONATI AGENT PUSHING DEVICE IN DOUBLE CYLINDER CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION cles.

To this end devices presently in use generally provide key means which fix the cylinders to the vertical shaft lowerly carrying the means which engage with the articles under manufacture. This arrangement however gives rise to disadvantages regarding the operations for varying the height of said vertical shaft, and also leads to appreciable constructional complications.

In some types a certain constructional simplification has been obtained by mounting said engagement means idly rotable at the extremity of said vertical shaft, but this case a tendency arises for the articles under manufacture to twist, even though the inertia forces in play'are small, with consequent maioperation of the pushing device.

SUMMARY OF THE INVENTION The main object of the present invention is that of obviating the abovementioned disadvantages by providing apushing device of rational structure and easy manoeuvrability, which reliably avoids the danger of twisting of the articles under manufacture, and is of simple construction. I

A further important object of the invention is that of providing a pushing device by means of which the manufactured articles are unloaded in a reliable and regular manner.

According to the invention, there is provided a pushing device for articles under manufacture on double cylinder circular knitting machines, comprising a substantially vertical cylinder fixed coaxially above the two needle cylinders, a piston slideably mounted in said cylinder and means for hydraulically feeding said cylinder, said device being characterized in that a pair of substantially vertical rods placed a short distance one from the other is coupled to said piston so that they rotate about its axis and pass through respective passages in a body rigid with said needle cylinders, and lowerly support the means which engage with the articles under manufacture.

BRIEF DESCRIPTION OF THE DRAWING Further characteristics and advantages of the invention will better appear from the detailed description of a pushing device for double cylinder circular knitting machines for the manufacture of mens socks and the like, illustrated by way of example with reference to the accompanying drawing in which the single FIGURE shows an axial section through said device.

DESCRIPTION OF THE PREFERRED EMBODIMENT with reference to the above FIGURE, the pushing device according to the invention comprises a cylinder 1 of considerable length fixed coaxially above the needle cylinders 2 and 3Q'More precisely the cylinder 1 is fixed, for example by screwing, to a collar 4 provided with lugs 4a by which it is fixed to a plate or support structure 5 forming part of the fixed structure of the machine.

A piston 6 provided with a lipped gasket 7 is slideably mounted in the cylinder 1 and lowerly coupled to two rods 8 disposed vertically a short distance one from the other and symmetrically with respect to the axis of the cylinder 1. More precisely the rods 8 are fixed to a disc 9 provided with a shank 9a which is attached coaxially to the piston with the interposing of a ball bearing 10. This latter is detained on the piston 6 by means of a plate 11. In this manner the unit comprising the rods 8 and disc 9 with its corresponding shank 94 can rotate about the axis of the piston 6.

Lowerly the rods 8 support, by way of a disc 12, a truncated conical body 13 disposed with its wider end downwards and provided there with points 14 adapted to engage with the articles under manufacture.-

The body 13 is rigid with the rods 8 and rotates together with them.

The rods 8 slide through corresponding holes in a sleeve 15 rotatably mounted in the collar 4. Lipped gaskets 16 are provided at the holes of the sleeve 15, whereas between said sleeve and the collar 4 there is a rolling bearing 17 of the seal type.

Between the piston 6 and sleeve 15 there is thus created a cylindrical sealed chamber which is fed with compressed fluid by means of a duct 18. as will be evident hereinafter.

Weights 19 for increasing the tension force may be inserted in the cylinder 1, above the piston 6.

The cylinder 1 is upperly closed by means of a cover 20.

In order to allow the truncated conical body 13 to rotate together with cylinders 2 and 3, the rods 8 slide through corresponding holes in a disc 21, fixed by means of screws 22 to the cylinder 2.

In this manner the rotation of the cylinder 2 causes the rods 8 to rotate and hence also the truncated conical body 13..

Operation of the pushing device according to the invention is as follows.

The unit comprising the truncated conical body 13, rods 8, piston 6 and it required the weights [9 placed above this latter is made to descend downwards under theaction of its own weight so as to put the articles under manufacture into a state of tension by engagement with the points 14 Said unit is raised by feeding the compressed fluid, for example compressed air, through the duct 18 into the cylinder 1. The compressed air cannot flow out downwards because of the seal formed by the bearings 17 and gaskets 16, thus the piston 6 is made to rise together with the truncated conical body 13.

Rotation of the needle cylinders-2 and 3 causes rota-- tion, by way of the disc 21, of the rods 8 and therefore of the body 13 rigid with it, whereas the piston 6 is not dragged into rotation because of the presence of the bearing 10.

In this manner the truncated conical body 13 with its corresponding points 14 rotates precisely together with the cylinders 2 and 3, eventhough free to vary in level.

The sequence of movements in the level of the truncated conical body 13 is as follows.

At the beginning of manufacture of the edge of a sock (after a few rows) feeding of compressed air to the duct 18 is made-to cease, at which the piston 6 descends downwards under the action of its own weight and the weight of the various elements associated with it, so that the truncated conical body 13 descends into the cylinder 2 until the points 14 are brought into engagement with the fabric being manufactured.

The fabric as it is produced is in this manner pushed downwards so as to be in a suitable state of tension, whereas the truncated conical body 13 rotates together with the cylinders 2 and 3. r

When manufacture arrives at the heel of the sock, before the reciprocating motion of cylinders 2 and 3, compressed air is introduced into the cylinder 1 through the duct 18, so as to raise the piston 6 and consequently the truncated conical body 13, whereas suction is set up from below so as to avoid the section of sock produced from rising together with the body 13.

After manufacture of the heel, the feed of compressed air to the duct 18 is stopped, so that the piston 6 redescends by its own weight and brings the truncated conical body 13 again downwards until the points 14 engage with the fabric.

When manufacture of the toe is reached, before the reciprocating motion of cylinders 2 and 3 necessary for such manufacture, the truncated conical body 13 is again raised by feeding compressed air to the duct 18. Also in this case the section of sock produced is prevented from rising upwards by applying suction from below.

When the sock is finished, it is unloaded by suction under the cylinder 3.

Atthis point the manufacture of a new sock can comand tensioning the fabric under manufacture. comprising a substantially vertical fluid operated cylinder arranged fixedly on said support structure, a piston slidable inside said fluid operated cylinder, two pushing rods arranged parallel to each other and symmetrically spaced with respect to the rotational axis of said needle cylinders, said rods being rotatably connected at one end to said piston and being provided at the other end with a fabric engaging body for engaging and tensioning the fabric during manufacture, and guiding means for said rods including a bearing arranged on said support structure below said fluid operated cylinder and having a central body provided with passages for guiding said rods and a peripheral ring portion fixed to said support structure, said guiding means furtherincluding a disc rigid with the upper of said needle cylinders and provided with through passages for said rods arranged symmetrically to said axis of said needle cylinders, thereby to cause the said rods to rotate together with said needle cylinders during axial movement of said rods provided by said slidable piston for pushing and tensioning said fabric under manufacture.

' a a a a a 

1. In a double cylinder circular knitting machine for the manufacture of stockings and the like, comprising two rotatable needle cylinders and a fixed support structure arranged thereabove, a device for pushing and tensioning the fabric under manufacture, comprising a substantially vertical fluid operated cylinder arranged fixedly on said support structure, a piston slidable inside said fluid operated cylinder, two pushing rods arranged parallel to each other and symmetrically spaced with respect to the rotational axis of said needle cylinders, said rods being rotatably connected at one end to said piston and being provided at the other end with a fabric engaging body for engaging and tensioning the fabric during manufacture, and guiding means for said rods including a bearing arranged on said support structure below said fluid operated cylinder and having a central body provided with passages for guiding said rods and a peripheral ring portion fixed to said support structure, said guiding means further including a disc rigid with the upper of said needle cylinders and provided with through passages for said rods arranged symmetrically to said axis of said needle cylinders, thereby to cause the said rods to rotate together with said needle cylinders during axial movement of said rods provided by said slidable piston for pushing and tensioning said fabric under manufacture. 